Pneumatic tool.



PATENTED J'NE ll, 190'?.

W. H. KELLER. PNBUDZIATC TOOL. APPLIOATION FILED JAN. 9.1906.

EA. |I-

PATENTBD .1U-NB 11, 1907.

W. 11. KELLER.

PNBUMATIC TOOL APPLICATION FILED JAN. 9

2 SHEETS-SHEET 2.

HMH: 11o

Jay@

UNITED V STATES PATENT FFICE.

'PNEUMATlC TOOL.

Specification of Letters Patent.

Patented J une 1 1, 1907.

Application filed January 9, 1906. Serial No. 295,230.

. which the following is a specification.

hammers 'impracticable My invention vrelates to a novel construetion ofa pneumatic tool and a valve mechani:-"n for a pneumatic tool whereincost of production is reduced to a ininilnmn and the constructiongristtl;Y simplified. Many attemptshave heretofore been made to produceLa valve mechanism which will accomplish the desired results, but so faras l am aware it has hitherto been considered im- -possible Aandimprueicable to employ the valve of symmetrical construction having bothends constructed alike and wherein the valve can be inserted in thevalve box, either end foremost, and wherein thel same type of valve andvalve box can be applied to a short stroke or to u longl stroke tool anda solid piston or a grooved piston may be employed with equal facility.

So fur as l am aware` l am the first in the art to produce a valvemechanism 'wherein it is possible to secure any desired length ofstroke. without materially changing the whole construction of thecylinder and ports. In many pneunmtie tools as heretofore constructedwlw-.rein a fluid actuated valve is used to control the movement of thehammer or piston, the valve has been moved either in un oppositedirection or a right angle to the movement of said hammer or pistoninwhich case the blow of the hammer will naturally interfere with theregular and uniform movement of the valve, if the. latter does not movein the same direction asthc piston, and if the Valve does not workregularly and uniformly the reciprocations of the. piston vill beirregular which is a very objectionable feature and very often rendersthe usc of pneumatic ThisV irregular movement of the hammering pistonsometimes also causes the valve to break or hecome injured and thusshortens the life of the tool. Since it will be apparent that if thevalve moves in the opposite direction to the piston shortly before thelatter strikes the chisel, or if theI valve should move in an oppositedirection to`the piston at the. moment that the piston delivers its blowthe valve will be liable to rebound from its seat, reopen ports thatshould be closed and cause the tool to jump; or in other words, thecylinder or casing will move away from the chisel or the working tool,because the exhaust from the back end does not occur at the right time.

Now, since hammers of the character of my novel construction underconsideration strike from two to three thousand blows per minute, it wil-be readily seen how wearing this irregular movement will be both on thevalve and the operator. By my novel invention, however, before thehammer strikes the chisel or workingtool, the valve will move in thesame direction and when the blow is delivered to the working tool thevalve foilowing the piston, the blow instead of rebounding the valvefrom thc seat will serve to hold said valveI more firmly seated, wherebyall the ports are posi tively o ened at the right time.7 the movementofthe iammer is regular and unobstructed under all conditions and thejumping or fluttering of the valve which has heretofore been anobjectionable feature in most pneumatic hammers is overcome. "l

A very objectionable feature in many pneumatic tools now on the marketarises from the excessive shock and .vibration caused bv the rapidreciprocations of the piston and for the other'reasons before specifiedwhich, in my present invention are reducedl to a minimum whereby myinvention can be applied not only to li ht work such vas cutting ordressing stone an calking boilers or ves-' sels, but for chipping andrivetin on metal and for performing varios kin s of-work ordinarily:heretofore performed by simple hand tools and a mallet or hammer.

To the above ends my invention consists broadly of a novel constructionof valve, and

-valve box, said valve being capable of being inserted'either end first,into the valve box and req-virili no other cover or machine work of thec aracter required when a valve j l 'box comprising two or more parts is'n.sed.

It frrther consists of a novel construction the valve, in their extremeforward position. l

Fig. 3 represents a section taken on the same line as Fig. 2 but showingthe valve in its rearmost position and ,the piston just com ple'ting itsforward movement, Fig. 4 rep resents a perspective view of my novelconstruction of valve employed in detached position. Fig. 5 represents alongitudinal sectional view of a long stroke pneu matic riveting hammerembodying my invention, the piston and valve being shown intheir eX-treme Jforwardposition. Fie'. 6 represents a sectional View taken on adi erent line from Fig. 5 and showing the piston and valve in thevrearward position they assume. Fig. 7 represents a sectional view of myinvention and embodied in a chipping hammer having a grooved piston, thepiston and valve being shown in. their extreme forward position. Fig. 8represents another view similar to Fi 7 but showing the Vlalve andpiston in adi?- ferent position. v

v,fSinfiilar numerals of reference indicate corresponding parts in thefigures:

Referring to the drawings: in the detailed description of my novelconstruction, l shall trace the course of the motive lrid from itsentrance into the handle which may be of any suitable .or conventionalconstruction and shall describe the passage of the motive Huid from thetime it enters the handle, passes through and beyond the valve on eitherside thereof and durin itsjinlet to either side of the piston and s alltrace the exhaust of the motive fluid from both ends ofthe piston andvalve,

Referring rst to Figs. 1 to 4 inclusive, it will be seen that when theparts a're in the position seen in Fig. 1, ,the motive fluid enters thepressure supply duct 1 inthe handle and flows thence into the passage 2and thence into the passage 3 of the valve box and thro'.. gh thevgroove4 of the valve box around the forward groove 5 of the valve 6, assumingthe latter to bain its rearmost position as seen in Figs. 1 'and 3. Themotive Hi id then passes thro; gh* the ports "Z of the valve box and thepassage 8 into the rear portion of the lpiston chamber 9 and assumingthat the piston 10 is in the position seen e in Fig. 1, said piston willbe driven iorwardlv l from the position seen in Fig. 1 into the positionseen in Fig. 2.

It will be observed that passages 11 and 12 of the valve box are alwaysopen to live air pressure and that when the valve is in the positionseen in Fig. 1, live air can pass freelythrough sa1d passages 11 and 12to the forward or left handportion of the valve chamber 22 and thence'tothe atmosphere' through the exhaust ports 23, it being understood that-while the piston is exhausting from its forward end the `valve 6 is inthe position seen in 'F ig. 3 wherein the relative location of theports'lQ and 21 will clearly appear. After the piston 1() has moved intothe position seen in Fig. 2 the port 24 is uncovered by' the 4pistonmoving beyond it, whereby live air is permitted to flow throu h the port25 passage 26 and port 24 into tlie piston'chamber and thence throughthe port 27 and passages 28 and exhaust port- 29 to the annular exhaustchamber 22 and thence to the main exhaust ports 23. The pressure uponthe torward end of the valve 6 is now relieved, whereupon the constantlive pressure exerted.4 through the live air port 14 will force thevalve 6 forwardly into the position seen in Fig. 2.

Fig. 1, the exhaust. from the rear or right.

hand endv of the piston takes place at first through 'the port 27,passages .28 and port` 29, annular hamber 22 und ports 23 to theatmosphere. Alter the piston l() has moved rearward or toward the handlesufficientlyto cover the port 27, as seen in Fig. 3, the exhaustcontinues to take place through the passage 5%, port groow` :'3 ol thevalve and passage 29, annular rlnunher 22 and ports 22% tothe atmosphereas soon in Fig. 'lhe piston l() has now moved rearvimdlv or toward thehandle into the position seen in Fig. 1 so that it uni-overs the port31. thereby permitting air in tho rear or right hand portion of thevalve chamber to esi-ape The piston 10 and the valve 6 being now intheir forward position, as

'through the passages and and ort 31 into t e piston chamber 9 andthence t rough the port 30, passage 28, port 29, annular chamber 22 landexhaust ports 2 3 to the atmosphere, thereby* causing the valve `to movefrom the position seen in Fig. 2 into theposition seen in Fig. l byreason of the live air ressure on the forward end of the valve w 'eh ispermitted through passages Itwillof course be understood that while thepiston is movingfrom the position seen the necks 5and`2v0valthough itwill be evident that this construction can be modified.

"It will be seen from the foregoing that the valve of kmy novelconstruction of valve mechanism is symmetrical at both ends and hasconstant pressure on both ends and is shifted byintermittent exhaust atboth ends. By making the valve as described the same can be cheaplyproduced by automatic maf ehiner and byreaso'n'of its being solid it isexcee ingly durable under all conditions and vsince the valve 'isconstructed the same at both ends, it canbe insert-ed in the valve boxeither end foremost so that there is no possibility of the tool beingimproperly assem- V bled in ease the valve and valve box aredisconnected for the purpose of inspection o1' re airs. I can employ thesame type of vave `mechanism for a long or short stroke orfor anylengthof stroke which it is desired .to impart to the piston and it will befurther apparent that the stroke of the piston is not Q A limited by thelength ofthe piston.

' B constructing the valve and valve box in t e manner described, I amenabled to have a valve mechanism consisting el' only two parts, thevalve and the valve box and since the piston and valve simultaneouslymove in the same direction or in unison vibrationis reduced to aminimum. By reason of the novel construction and collocation ofthe portsand passages intermediate the valve and piston, the tool will readilystart in any position in which it may be held in the hands of theworkman.

In the construction seen in Figs. 5 and 6, I

'- have shown my novel..valve mechanism as applied to a long stroketool, that is a tool having a e linder 37 of such length that the strokeof .t le piston is considerably in excess of its own length and since mysame novel valve mechanism can be employed in this type of tool, ,asalready described, I have designated all the parts comprising the same,

seen in Figs. 5 and 6, by the same reference lletters as used forcorrespomling parts in the corresponding Flgs. 2 and 1 respectively.

In Figs. 5 and I have shown the piston employed as cmnprising a plain,ungrooved, solid, cylindrical shaft 38 el' uniform dialnetcr throughoutits length both ends being of approximately thesame contour anddiameter. I have shown the type of tool illustrated in Figs. 5 and 6 asbeing equipped especially for riveting, the riveting die heiligindicated at 39 and having the shank 40 projecting into the end ol' thetool cylinder 37, said riveting die being held in position by means ofthe clip or clamp 4l oi' the usual construction. l have shown the handle42 omitted from l `igs. 5 to S inclusive, although it will of course beunderstood that a handle is to be employed in conjunction with all ofthese tools when the same are used l'or met-al work.

In the construction seen in Figs. 7 and S, l have shown anotherembodiment of the prin ciple of my inventit-,n as applied to a shortstroke chipping er ealking hammer wherein the piston 43 having a groove-/l-'l is employed, said groove connecting the smaller head 45 of thepiston to the body of the latter. l have sl'iown precisely the same typeand arrangement of valves, ports and passages as appears in Figs. 2 to 5already described and l have consequently lettered the correspondingparts with corresponding reference ligures and inasmuch as the samecycle oi operation and the samd coaeting ports and passages are employedthroughout the tool seen in Figs. 7 and 8 as is employed in the toolseen in Figs. l, 2', 3 5 and o, l have deemed it unnecessary to describeFigs. 7 and 8 in detail er to illustrate the same by a View similar toFigs. l or ti, since the corresponding parts will all appearsubstantially the same.

So far as l am aware., l am the iirst in the art to devise a valvemechanism which can be used interchangeably with cylinders ol' varyinglengths as will be apparent from Figs. l to 3 and 5 to H and .my claimsto these features are therel'ore to be interpreted with correspondingscope.

lfVhile l have shown the tool cylinder and valve. box and valve as beingassembled by merely screwing the handle and sleeve 4G in position uponthe tool cylinder, it will be evident that various other means ofsecuring the, handle., tool cylinder, `valve box and valve in assembledposition may be emn fployed without departing `from the spirit of' myinvention.

I desire to lay special emphasis upon the cheapness with which my valvemechanism can be produced, since there is no cap or cover required forthe rear end of the valve box as is usually customary and since I makellO the inner wall of the handle serve as the cover for the valve boxsaid inner Wall thus forms a stop 'for the rearward movement of thevalve and also serves to contain the port 14 through which live motiveHuid is constantly acting. l `urthermore,` it will he apparent that whenthe valve is in one position it will be held in that position positivelyand firmly and cannot he moved or shaken, since there is absoluteexhaust on one end of the valve and 'absolute pressure on the other endas long as the proper ports are covered and vice versa when they are ocned. it will be evident tlhat in my invention I accomplish the sameresult with a valve havino' equal pressure areas that has heretofore onybeen possible Where a valve having differential ressure areas wasemployed yalso that theatter construction is considerably more ex ensiveand com licated and less durable than, that employe in my invention.A Itwill be apparent that a plurality of ports and passages corresponding tothe ones shown may be em loyed and that the length and diameter of t eseports may be proportioned by the constructor to suit the re nirements orthe occasion and I do, not, t ereore, desire to be limited in everyinstance to the'exact construction I have herein shown and described.

ingeving thus described my invention, vhat I claim' as new and desire tosecure by Letters Patent, is v i l. In a pneumatic tool, a balancedvalve, composed oftvvo outer ungrooved heads and a central head all ofuniform diameter, necks joining said heads, a valve box, having arearwardly extending valve chamber, means for directing constant ressureupon said outer heads of said va ve, and means for creating an exhaustpassage intermittently at eaclend o1 said valve, said valve and valvebox bei-ng in alinement with their psl 2.' ln a pneumatic tool, acylinder, a piston a valve `in said chamber 1n alinement with Y said.piston and, having a pluralitycf ungrooved heads of uniform diameterjom'ed by necks, an inlet groove in said valve chamber controlled bysaid valve,` ports and passages controlled by said valve for leading themo tive iluid toward and away from the ends of said piston, portsleading into the front and rear portions of said valve'chamber foradinitting live motive fluid constantly to the ends ofsaid valve, andpassages controlled by the piston for permittin y intermittent ex*haiist from the ends of sai( valve.

3. ln a pneumatic tool, a cylinder, apiiston therein, avalve box, avalve chamber open at its rear end, a valve-in said chamber, havi acentral head and two outer ungloove heads ci' uniform diameter joined bynecks, an inlet groove in said box, controlled by said central head,

lluid toward and away from the ends of said piston. ports leading intothe iront and rear fr. ln a pneumatic tool, a cylinder, a coverlessvalve box rnade in one piece, a balanced valve therein inalinement withsaid cylinder and having equal pressure areas formed oi solid heads oithe same diameter, means for directing constant pressureupon the outerarea of each of said heads, and a handle secured to said cylinder and.having its inner wall contacting with the rear wall of said valve box soas to form the rear closure'for said valve box.

5. In a neumatic tool, a cylinder, a cover less valve ox made in onepiece, a balanced valve therein having constant pressure on its ends,and a handle secured to said cylinder and having its inner Wallcontacting with the rearwall of said valve box sc as to form the rearclosure for said valve box, in combination with means for creating anexhaust assage intermittently at each end or" said va ve.

6. In a pneumatic tool, a cylinder, a valve chamber, a balanced valve inalinement with said cylinder and having heads of eoual diam eter adaptedto'be inserted in said chamber either end foremost, a handle secured tosaid ylmder, and having its' inner Wall forming a c c osure lor saidvalve chamber, a main presfsure supply duct leading through said handleto said valve box, eport leadingfroni said suply duct to the rear end olsaid valve chamber, roi' conducting live motive fluid constant! fthereinto, and a second port leading through 'said valve box, ,forconducting live motive fluid constantly to the front end of said valve.

7. lne pneumatic tool, a cylinder, a valve -box having a valve chamberopen at its rear end, a balanced valve in alinement with said cylinderand having heads of equal diameter adapted to be inserted in saidchamber either end foremost, a grasping handle secured to said cylinder,and having its inner wallliorming a closure for said valve chamber, amain )rassure sup ly duct leading through said andle to sai valye box, aport leadin from said su )ply duct to the rear end o said valve chamber,for conduct'g livejmotive fluid constantly thereinto, and a second por-tleadilng through said valve box, for conducting live motive fluidconstantly to the front end of said valve.

8. In a pneumatic tool, a valve for controllinor ports common Vtheretoand to a piston orts and passages con- Y trolled by said hea s, forleading the motive Y being located exteriorl suenos A termitteiiftl'y tothe exhaust and said valve y to said piston in alinement therewith anadapted to move in `the vsame direction as said piston.

a pneumatic tool, a solid piston, a valve adapted to move in the samedirection as the latter, said valve consisting of a body rovided withthe outer and intermediate e'ads joined h necks, said outer heads beingungrooved an always exposed to'live fluid pressure and said central headbeing alter-- ynately ex osed on either side to a greater,

volume o live fluid pressure, said heads be ing of the saine diameterand said valve being located out of the'path of said piston, the

- movement of the latter terminating exterior to said valve and thelatter being provided with exhaust passages which are openintermittently at each end of said valve.

10. In a pneumatic tool, the combination of acylinderja piston, portsand passages for conducting the motive fluid to and from said piston, aone piece valve box secured to an 'end of said clindcr and a solidbalanced valve having eads of uniform diameter in said valve box, theouter ends of said valve f being ungrooved and always ex osed to livefluid'pressure and intermittent to the exhaustsaid valve being locate(out of the path of said piston and movinfT in the same direction as saidpiston when the latter is in thelact of striking a blow uponthe workingtoo 11. In a pneumatic tool, a valve consisting of a solid body havingtwo ungrooved outer and intermediate heads, necks joining said heads,the area of said outer heads being the same and having live motive fluidconstantly acting thereupon, said heads being o en intermittently to theexhaust and sai( valve being out of the path of the piston iiialinenient therewith and moving in the same direction as said piston.

12. In a pneumatic tool, the combination of a cylinder containing' apiston, a one piece valve box located out of the path of the piston, anunapertured valve in said valve box, the movement of said piston beingin line with said valve and terminating exterior to said valve whichlatter-is provided with opposing pressure areas against which livemotive fluid constantly acts, said o )posing pressure areas-being of thesame diameter and intermittently open to exhaust and said valve movingin the same direction 'as said piston. l

13`. In a pneumatic tool, a cylinder, a piston therein, a one piecevalve box, an una ertured valve therein moving in the same i- `sai ".24,port 27, passages 2S and port 29 for per-- rection as said piston inline therewith and located at the rear and out oi the path thereof, themovement of said piston terminating exterior to said valve, a handleengaging said cylinder and forming the assemb ing means for said valvebox and cylinder, avalve, a pressure supply duct of comparatively largearea leading to said valve chamber and live airr passages of a reducedarea leading from the pressure supply duct of said handle to the ends ofsaid valve chamber.

14. In a pneumatic'tool, a'cylini'ler, a one niece valvebox located atan end thereof, a iandle having thereon means engaging said cylinder forholding the latter, and said valve box in assembled position, avalve insaid valve box, a pressure supply duct leading from said. handle intosaid valve box, a

groove in the latter for leading motive fluid to opposite portions ofsaid valve, live air passages 14, 11 and 12 for leading a restrictedsupply of live motive luidginto cach end of valve box, the port 25,passage 26, port mtting exhaust of motive fluid from the foirz Ward endof said valve, a port 32, passage 33,

port 31 and port 3() for permitting exhaust of i the motive fluid fromtherein' end of said valve, said ports 30 and 27 being controlled by thepiston as it nears the extreme limit ofi its stroke, in each direction,passages 7 and 8u in said valve box for permitting the entrance ofmotive fluid to drive the pistou forwardly, said passages serving asexhaust assages as the piston moves in a rearwur direction, iassages 19,18 and 17 for permitting the inlet of the motive fluid to drive thepiston rearwardly and a assage 21 serving in conjunction with saipassages 19, 1S and 17 .to permit exhaust from the'forward end of saidpiston when the latter moves in a forward direction.

15. In a pneumatic tool, a cylinder', a piston therein, a valve box, a'solid balanced valve therein having three heads of unilorin diameter,said valve moving in substantial alinement with said piston, means'lor'direct`4r ing constant pressure upon each outer head of said valve,and means lor creating exhaust intermittently at cach end of said valve,

he used interchangeably with a solid or'ui1- groovcd piston, or with along stroke or short stroke cylinder.

loi

whereby the same valve and valve box camita

